Justification:
Listed as Critically Endangered because of a very significant decline in population over the previous three generations (which in this species represents approximately 30 years). This decline is inferred to be a 90% reduction in population. The causes of this decline are understood, are reversible, and have ceased at least for a substantial part of the total species population (i.e. that which occurs in the Torricelli Range). The population in the Torricelli Range is now effectively protected by the Tenkile Conservation Alliance (www.tenkile.com). Early indications are that it is recovering as a result of protection. If this recovery continues, it is likely that the species will soon shift in status from CR to EN. The other known population of the species is not protected and may be in continuing decline due to reduced area and quality of habitat and loss of mature individuals by hunting.

This species is now known only from two area of New Guinea: The Torricelli Range in Papua New Guinea from Weight to Kuliek, and the Foja Mountains in West Papua. There are fossil records from Vogelkop Peninsula in West Papua and other places. There are unconfirmed sightings from the Prince Alexander range of Papua New Guinea. It has been extirpated from most of its historic range. It has been recorded at elevations between 680 and 1,700 m a.s.l.

In Papua New Guinea, the population in the Torricelli could be as high as 500 (J. Thomas pers. comm. 2015), although this figure awaits confirmation. Beginning in 2006, this population has been protected by a community-based conservation program managed by the Tenkile Conservation Alliance (http://www.tenkile.com). This program includes a hunting moratorium agreed by 30 villages within the range of the species in the Torricellis. As a result hunting pressure on this species has been significantly reduced and it is likely that numbers have begun to increase. There is no quantitative information on the size of the Foja Mountains population, but it is likely to be small.

Historically, the species has been highly threatened by hunting for food, and additionally by habitat loss through conversion of forest to cultivated land. The lowland areas of its distribution are earmarked for deforestation and oil palm expansion. Effective conservation efforts by the Tenkile Conservation Alliance (http://www.tenkile.com/weimang-tree-kangaroo.html) involving landowners of the species range in the Torricelli range have resulted in recent substantial decline of hunting of the species in the Torricelli part of its range. Continuation of this program should allow significant increase of this population.

The Torricelli population is protected by the community-based conservation program of the Tenkile Conservation Alliance (http://www.tenkile.com/weimang-tree-kangaroo.html). There is an urgent need to survey the Foja and Prince Alexander ranges for this species and to protect any remaining populations through the development of protected areas, hunting regulations, and local awareness programmes. Continuation and extension of the work of the Tenkile Conservation Alliance is essential for the persistence and recovery of this very rare species.

In-Place Research, Monitoring and Planning Systematic monitoring scheme:YesIn-Place Land/Water Protection and Management Conservation sites identified:Yes, over part of range Occur in at least one PA:YesIn-Place Species ManagementIn-Place Education